[PATCH] cgroup_rm_file: don't delete the uncreated files

[PATCH] cgroup_rm_file: don't delete the uncreated files

[Gao feng]

in cgroup_add_file,when creating files for cgroup,
some of creation may be skipped. So we need to avoid
deleting these uncreated files in cgroup_rm_file,
otherwise the warning msg will be triggered.

"cgroup_addrm_files: failed to remove memory_pressure_enabled, err=-2"

Signed-off-by: Gao feng <gaofeng-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>
---
 kernel/cgroup.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 5cc3724..6928b3e 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -932,6 +932,12 @@ static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
 	lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex);
 	lockdep_assert_held(&cgroup_mutex);
 
+	/* does @cft->flags tell us this file isn't created on @cgrp? */
+	if ((cft->flags & CFTYPE_NOT_ON_ROOT) && !cgrp->parent)
+		return 0;
+	if ((cft->flags & CFTYPE_ONLY_ON_ROOT) && cgrp->parent)
+		return 0;
+
 	list_for_each_entry(cfe, &cgrp->files, node) {
 		struct dentry *d = cfe->dentry;
 
-- 
1.7.7.6

Re: [PATCH] cgroup_rm_file: don't delete the uncreated files

[Gao feng]

on 2012/12/06 11:09, Gao feng wrote:
> in cgroup_add_file,when creating files for cgroup,
> some of creation may be skipped. So we need to avoid
> deleting these uncreated files in cgroup_rm_file,
> otherwise the warning msg will be triggered.
> 
> "cgroup_addrm_files: failed to remove memory_pressure_enabled, err=-2"
> 
> Signed-off-by: Gao feng <gaofeng-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>
> ---
>  kernel/cgroup.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/kernel/cgroup.c b/kernel/cgroup.c
> index 5cc3724..6928b3e 100644
> --- a/kernel/cgroup.c
> +++ b/kernel/cgroup.c
> @@ -932,6 +932,12 @@ static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)

oops,cft may be NULL,I miss the check of cft in this patch.
Please ignore this patch,I will resent it.

Re: [PATCH] cgroup_rm_file: don't delete the uncreated files

[Li Zefan]

On 2012/12/6 11:09, Gao feng wrote:
> in cgroup_add_file,when creating files for cgroup,
> some of creation may be skipped. So we need to avoid
> deleting these uncreated files in cgroup_rm_file,
> otherwise the warning msg will be triggered.
> 
> "cgroup_addrm_files: failed to remove memory_pressure_enabled, err=-2"
> 
> Signed-off-by: Gao feng <gaofeng-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>
> ---
>  kernel/cgroup.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/kernel/cgroup.c b/kernel/cgroup.c
> index 5cc3724..6928b3e 100644
> --- a/kernel/cgroup.c
> +++ b/kernel/cgroup.c
> @@ -932,6 +932,12 @@ static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
>  	lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex);
>  	lockdep_assert_held(&cgroup_mutex);
>  
> +	/* does @cft->flags tell us this file isn't created on @cgrp? */
> +	if ((cft->flags & CFTYPE_NOT_ON_ROOT) && !cgrp->parent)
> +		return 0;
> +	if ((cft->flags & CFTYPE_ONLY_ON_ROOT) && cgrp->parent)
> +		return 0;
> +

We should move those checks to cgroup_addrm_files() to avoid code duplication.

>  	list_for_each_entry(cfe, &cgrp->files, node) {
>  		struct dentry *d = cfe->dentry;
>  
> 

Re: [PATCH] cgroup_rm_file: don't delete the uncreated files

[Gao feng]

于 2012年12月06日 14:02, Li Zefan 写道:
> On 2012/12/6 11:09, Gao feng wrote:
>> in cgroup_add_file,when creating files for cgroup,
>> some of creation may be skipped. So we need to avoid
>> deleting these uncreated files in cgroup_rm_file,
>> otherwise the warning msg will be triggered.
>>
>> "cgroup_addrm_files: failed to remove memory_pressure_enabled, err=-2"
>>
>> Signed-off-by: Gao feng <gaofeng-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>
>> ---
>>  kernel/cgroup.c |    6 ++++++
>>  1 files changed, 6 insertions(+), 0 deletions(-)
>>
>> diff --git a/kernel/cgroup.c b/kernel/cgroup.c
>> index 5cc3724..6928b3e 100644
>> --- a/kernel/cgroup.c
>> +++ b/kernel/cgroup.c
>> @@ -932,6 +932,12 @@ static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
>>  	lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex);
>>  	lockdep_assert_held(&cgroup_mutex);
>>  
>> +	/* does @cft->flags tell us this file isn't created on @cgrp? */
>> +	if ((cft->flags & CFTYPE_NOT_ON_ROOT) && !cgrp->parent)
>> +		return 0;
>> +	if ((cft->flags & CFTYPE_ONLY_ON_ROOT) && cgrp->parent)
>> +		return 0;
>> +
> 
> We should move those checks to cgroup_addrm_files() to avoid code duplication.
> 

Get it,and the null check of cft in cgroup_rm_file is no need too.
Thanks!